Bridging plug for oil wells



June 9, 1931. c, H. SWEET ET AL BRIDGING PLUG FOR OIL WELLS Filed May 21 Zzgl kiki

Poema June 9, 1931 l 1,809,080

UNITED STATES PATENT oFFicE CECIL E. SWEET, OF BREA, AND EMMET F. COOPER, OF LON'G BEACH, CALIFORNIA BRDGIN'G PLUG FOR OIL WELLS l Application led Hay 21, 1929. Serial No. 364,806.

The chief object of this invention is to and are slidable on outwardly inclined doveprovide a plug which may beeasily lowered tail guides 24 meshing with corresponding in a well casing and quickly set at any degrooves in the slips, the projections beto prevent water from the formation enter- The slips 20 serve to hold the plug from sired depth therein to form a barrier for ing reinforced by backing of thin sheet the usual cementing-off operation in order metal 25.

is uing the casing above the oil z`one. downward movement after the plug has Another object of this invention is to) been set, and are indirectly connected to provide a bridge plug constructed in such the mandrel 14 b pins 26, the outer ends manner that after the plug has been located extending throug holes 27 in the slips, G9 and set at the desired depth in the well castheir inner ends being screw-threaded or ing any downward pressure thereon will otherwise secured to an annular flange 28 tend to tighten or hold it in place. formed on the mandrel. Centrally disposed A further object of this invention is to slots 30 are formed in the reduced tapered provide a plug constructed insuch manner portion 31 of the body to accommodate G5 that it may be inserted and set in aconduit movement of the pins 26. In order to lower by a setting tool, and released therefrom bg' the plug into the well it is necessary to conpulling the setting tool, the action of whic tract or draw the slips 20 inward so their will disconnect the setting tool from the teeth 2 1 will not engage the wall of the casv plug. ing, this being accomplished by forcing the 79 Other objects and advantages will appear mandrel dOWIIWaITd by means of a setting from the following dise1osure in whiehgtool 32, the lower end of which rests on the Fig, 1 is e Seotione1 view of the brid o upper end of the mandrel as shown inA Fig. 1. plug as it appears while being lowered in Durmg a downward movement of the. the Casin mandrel an expansion coil spring 34, 'f5

Fig. 2 1s a view Similar to Fig, 1 showing mounted 0n the mandrel 14 between the the bridge plug after it has been set, iiange 28 and a shoulder 36 formed at the Figs. 3 and 4 are sectional views taken on Juncture ofthe bores 12 and 15, is comlines 3 3 and 4--4 of Fig, 2, l pressed. In order to maintam the slips 20 Fig. 5 is a sectional view teken on line 1n a contracted position a plurality of links B0 5 5 of Figg 1, 38, preferably formed o wire, are con- Fig. 6 is a sectional view taken on line IleCtGd t0 the Seftmg 11001 32 and the plug 6 6 of Fig. 2. 10 through ears 40 on the setting tool and Referrin by numerals to the drawings, ears 42 on a head or block secured to the the body o the bridge plug is designated at upper end of the body, it being understood 85 v10 and is of cylindrical form and construct- Phat the links. are @Ollllfcted Pl`10l .t0 inserted of wood or other suitable material in orlllthplug 1n the Casing der that it may be drilled through after ackmg 46 Preferably formed from a the cement has set. pliable material, such as leather, and in the I A bore 12 is formed in the center of the form of a disk having a circular flange 47 90 plugr through'whieh assess, tubular manadapted to engage the inner wall of the dre 14, its lower end) extending through a, casing is positioned between the body and counterbore 15, and has secured to the porthe head 44, the head and Packillgi6 havtion extending below the lug a pair of ing openings 48 and 49 respectively through bow springs 18, their ends eing axed to which the setting tool ma pass, the head 9 collars v19 rigidly mounted in position on being secured to the body y lag screws 50. the mandrel, their functions being described A plurality of shps 52 having teeth 53 hereinafter. adapted to engage the casin on an upward Oppositely ldisposed. slips 20 having teeth movement of the plug are slidably mounted 2l are positioned about midway of the body in recesses 54 provided with thin metal lin-l '10G 1n 55, the slips having bevelled edges 56 in orer to prevent them from being disengaged from the body of the plug. The flap valve 60 is hinged at 61 to a plate 62 having an opening 63 thereinand secured to the head by the lag screws 50, the valve closing the opening in the head 4:4 when the plug is set.

In operation the slips 20 are contracted and retained in such positionby the links 38, the setting tool and other parts then assuming the respective positions shown in Fig. 1. The setting tool is then connected to suitable lowering tools 64 by a coupling 65 and lowered in the casing C to the required depth, fluid in the casing passing through the openings in the mandrel, setting tool, head, and lowering tools.

In order to set the plug the lowering tools are pulled upward, which operation will cause the lslips 52 to engage the casing and thereby prevent the plug from raising. Continued pull on the setting tool will then break or disconnect the links connecting the setting tool to the plug, thereby releasing the setting tool. Instantaneously upon release of the setting tool the bodyv of the plug will be forced downwardly due to the expansion of thecoil spring 34, and during such downward movement of the body the mandrel is held in a iixed position by the `bow springs 18, thereby causing the slips to expand against and engage the casing. After the setting tool has beenremoved from the plug, the valve 60 will automatically close the opening in the head 44 as shown 1n Fig. 2. Cement may then be poured on top'of the plug, the valve 60 and packing 46 preventing any fluid or cement passingl through or around the plug.

From the above construction it will be seen that after the setting tool has been released any downward pressure on the plug will tend to tighten it.

We claim:

1.. bridging plug comprising a body member carrying an assembly of slips adapted to be engaged to a Wa ll of a well casing into which the bridging plug has been inserted on a downward movement of the same, a second assembly of slips adapted to engage the wall of the casing on an upward movement of the body member, a compression spring engaging the mandrel and normally holding the first mentioned assembly of slips out of engagement with the wall of the casing while the plug is being lowered into position, means for expanding the first assembly of slipsinto engagement with the wall Aof the casing to plug the same, a packing member at the top of the body member for closing the casing above said body member, and means to lower said bridge plu -into the well. n

2. A bri ging plug for oil wells comprising a body member provided with a bore extending therethrough, a plurality of wall gripping members slidably mounted on said` the mandrel to compress the sprin where-l by the slips are maintained out o engagement with the casing until the body is positioned therein, a second set of slips secured in movable relation to the body member at the upper end thereof, a packing disk at the upper end of said body member for closing the casing above the body member, a frangible means connecting the setting tool and the body member, whereby when a pull is exerted on the setting tool the frangible means will be fractured to release the setting tool and cause an operation of the mandrel to set the slips, and a flap valve on the upper end of the body member for closing the bore after a plugging operation.

In testimony whereof we affix our signatures.

CECIL H. SWEET. EMMET F. COOPER. 

